Siloxane-oxyalkylene copolymers and use thereof



United States Patent Ofitice 3,483,240 Patented Dec. 9, 1969 ABSTRACT OFTHE DISCLOSURE New siloxane-oxyalkylene copolymers contain monoalkyl ormonoaryl ethers of polyalkylene glycols attached to silicon-bondedalkylene groups through carbamate linkages. These copolymers areprepared by reacting an alkenyl' isocyanate, such as allyl isocyanate,with a polyalkylene glycol monoether to form a urethane and thenreacting the urethane with an organopolysiloxane containingsilicon-bonded hydrogen groups to produce the siloxane-oxyalkylenecopolymer. Copolymers containing up to about 0.5 oxyalkylene group persilicon atom are useful as urethane foam surfactants and those havingmore than about 0.5 oxyalkylene groups per silicon atom are useful assensitizers for heat-sensitive latices.

This application is a continuation-in-part of my application Ser. No.512,208 filed Dec. 7, 1965, now abandoned, and assigned to the sameassignee as the present invention.

This invention relates to siloxane-oxyalkylene copolymers and to the useof some of these copolymers as urethane foam surfactants. In particuiar,this invention is directed to a new class of siloXane-oxyalkylenecopolymers having a urethane linkage therein and to the use of certainof these copolymers.

More particularly, this invention relates to siloxaneoxyalkylenecopolymers having the formula:

where R is an organic radical attached to silicon through asilicon-carbon linkage, -R is a member selected from the classconsisting of lower alkyl radicals, e.g., alkyl radicals containing from1 to 7 carbon atoms, and aryl radicals; A is a divalent hydrocarbonradical containing no more than about seven carbon atoms; a has a valueof from 0.05 to 1.00, inclusive; b has a value of from 1.12 to 2.25,inclusive; the sum of a plus b is equal to from 2.02 to 2.40, inclusive;n has a value of from 2 to 4, inclusive; and x has a value of at least5, e.g., from 5 to 100 or more.

The siloXane-oxyalkylene copolymers of Formula 1 are liquids or softwaxes and are useful as surface active agents because of the differentsolubility characteristics of the siloxane portion and the oxyalkyleneportion of the copolymer. The uses for these surface active copolymerswithin the scope of Formula 1 include the use of these materials assurfactants in the preparation of emul sions of organopolysiloxanes withvarious aqueous materials. In addition to this common utility of all ofthe siloxane-oxyalkylene copolymers within the scope of Formula 1,certain classes of these siloXane-oxyalkylene copolymers areparticularly useful for special purposes.

Those siloxane-oxyalkylene copolymers within the scope of Formula 1which have the formula:

where R, R, A, n and x are as previously defined, g has a value of from0.05 to 0.5, inclusive, h has a value of from 1.52 to 2.25, inclusive,and the sum of g plus 11 is equal to from 2.02 to 2.40, inclusive, areuseful for the emulsification, nucleation, and stabilization of flexibleand rigid polyurethane foams, which foams are prepared by conventionaltechniques from polyols and various polyisocyanates.

' Those siloXane-oxyalkylene copolymers within the scope of Formula 1which have the formula:

where -R, R, A, n and x are as previously defined, j has a value of from0.50 to 1.00, inclusive, k has a value of from 1.12 to 1.90, inclusive,and the sum of j plus k is equal to from 2.02 to 2.40, inclusive, areparticularly useful as sensitizers for heat-sensitive latices as will bedescribed in more detail hereinafter.

The radicals represented by the various letters appearing in structuralFormulae 1, 1a, and 1b are well known in the art and are typified by theradicals usually asso ciated with silicon-bonded organic groups in theCase of R, the radicals generally associated with monoalkyl ethers ofpolyalkylene glycols in the case of R and the usual divalent hydrocarbonradicals in the case of A.

The organic radicals represented by R include monovalent hydrocarbonradicals, halogenated monovalent hydrocarbon radicals, and cyanoalkylradicals. Illustrative of specific radicals within the scope of theseclasses can be mentioned, for example, alkyl radicals, e.g., methyl,ethyl, propyl, butyl, octyl, etc. radicals; aryl radicals, e.g., phenyl,tolyl, Xylyl, naphthyl, etc. radicals; aralkyl radicals, e.g., benzyl,phenylethyl, etc. radicals; olefinically unsaturated monovalenthydrocarbon radicals, e.g., vinyl, allyl, cyclohexenyl, etc., radicals;cycloalkyl radicals, e.g., cyclohexyl, cycloheptyl, etc., radicals;halogenated monovalent hydrocarbon radicals, e.g., chloromcthyl,dichloropropyl, 1,1,1 trifiuoropropyl, chlorophenyl, dibromophenyl, etc.radicals; cyanoalkyl radicals, e.g., cyanoethyl, cyanopropyl, etc.radicals.

The lower alkyl radicals within the scope of R include, for example,alkyl radicals containing from 1 to 7 carbon atoms, both straight chainand branched chain. The aryl radicals within the scope of R includephenyl, tolyl, Xylyl, naphthyl, etc. radicals. Illustrative of thedivalent hydrocarbon radicals within the scope of A of Formulae 1, la,and 1b are divalent aliphatic hydrocarbon radicals, such as methyleneand ethylene, as well as divalent aromatic hydrocarbon radicals, such asthe various isomeric phenylene radicals and substituted phenyleneradicals. In the preferred embodiment of my invention, R is methyl, R isa lower alkyl radical such as butyl, and A is methylene.

The siloxane-oxyalkylene copolymers Within the scope of the presentinvention, and the scope thereof, can best be understood by the methodof preparing these materials. This method of preparation involves thereaction of an unsaturated isocyanate having the formula:

with the monoalkyl or monoaryl ether of a polyalkylene glycol having theformula:

(3) n zn)x to form'a urethane having the formula:

(4) R(OC,,H OOCNH-ACHCH The urethane of Formula 4 is then reacted withan organohydrogenpolysiloxane having the formula:

to form the copolymer of Formula 1. In the above Formulae 2 through 5,the various letters and subscripts are as previously defined.

The isocyanates within the scope of Formula 2 are well known in the art,with the most common and preferred member of the class being allylisocyanate, which is within the scope of Formula 2 when A is methylene.

Also of interest and use in the practice of the present invention areother isocyanates within the scope of formula 2, such asp-vinylphenylisocyanate, vinylethylisocyanate, etc.

The polyalkylene glycol monoethers within the scope of Formula 3 arealso well known in the art. These materials are formed by reacting amonohydric alcohol of the formula ROH with an alkylene oxide or mixtureof alkylene oxides. By controlling the reaction conditions during thereaction between the aforementioned monohydric alcohol and thepolyalkylene oxide, the molecular weight of the polyalkylene glycolmonoether can be controlled. While any polyalkylene glycol monoetherwithin the scope of Formula 3 can be employed in the practice of thepresent invention, it is preferred that the material contain at least 5oxyalkylene units, i.e., x of Formula 3 is equal to at least 5. In manycases, it is desirable to have x equal to slightly more than 5 as aminimum so as to produce the preferred polyalkylene glycol monoethersemployed in the practice of the present invention which are those havinga molecular weight of from about 300 to about 5,000. As indicated byFormula 3, the polyalkylene glycol monoethers contain oxyalkylene groupsof from 2 to 4 carbon atoms. Included within these oxyalkylene groupsare, for example, oxyethylene, oxypropylene-1,2, oxypropylene-1,3,oxybutylene-1,2 etc. The monoether of formula ,(3) can contain allsimilar oxyalkylene groups or a mixture of oxyalkylene groups. In thepreferred embodiment of my invention, the oxyalkylene groups are amixture of oxyethylene groups and oxypropylene-l,2 groups. Where amixture of ethylene oxide and propylene oxide groups is employed, it isgenerally preferred to have the oxyethylene groups constitute about to75% by weight of the total weight of the monoether. Many of thepolyalkylene glycol monoethers employed in the practice of the presentinvention are described in Patents 2,425,755 and 2,448,644.

The organohydrogenpolysiloxanes within the scope of Formula 5 are alsowell known in the art and, as indicated by Formula 5, theorganohydrogenpolysiloxane contains an average of from 0.05 to 1.00silicon-bonded hydrogen atoms per silicon atom. Since there are morethan 2.00 total hydrogen atoms and R groups per silicon atom in theorganohydrogenpolysiloxane of Formula 5, it is apparent that thepolysiloxane is actually a copolymer of two or more ditferent types ofsiloxane units. Thus, the organohydrogenpolysiloxane of Formula 5 can bedescribed as a copolymer of one or more types of siloxan: units havingthe formula:

where R is as previously defined and c is a whole number equal to from 1to 2, inclusive, preferably 1, d is a whole number equal to from 0 to 2,inclusive, and the sum of (7) a ier:

where R is as previously defined and e is a whole number equal to from 0to 3, inclusive. The proportions and types of the siloxane units offormula 6 and the siloxane units of Formula 7 are selected so as toproduce a copolymer containing from 0.05 to 1.00 hydrogen atoms persilicon atom and from 1.12 to 2.25 R groups per silicon atom, with thesum of the number of hydrogen atoms and R groups being equal to from2.02 to 2.40 per silicon atom. The organopolysiloxanes within the scopeof Formula 5 can be prepared by the cohydrolysis of one or morehydrogen-containing ehlorosilanes, such as trichlorosilane,dichlorosilane, methylhydrogendichlorosilane,phenylhydrogendichlorosilane, dimethylhydrogenchlorosilane,methylphenylhydrogenchlorosilane, etc., with one or more otherorganochlorosilanes', such as methyltrichlorosilane,dimethyldichlorosilane, trimethylchlorosilane,methylphenyldichlorosilane, etc., to produce the siloxane within thescope of Formula 5, all of which is well known in the art.

One of the preferred types of organohydrogenpolysi- 'loxanes within thescope of Formula 5 used in preparing the siloxane-oxyalkylene copolymersof the present invention are the triorganosilyl chain-stopped copolymersof diorganosiloxane units and organohydrogensiloxane units having theformula:

where R is as previously defined, p has an average value of from 0 to45, inclusive, q has a value of from 1 to 48, inclusive, the sum of pplus q is equal to from 3 to 48, and where the sum of the silicon-bondedR groups plus the silicon-bonded hydrogen is equal to from 2.04 to 2.40per silicon atom. In the preferred embodiment of my invention, all ofthe R groups are methyl.

The several reactions which are employed to prepare thepolysiloxane-oxyalkylene copolymer of Formula 1 are relativelystraightforward. The reaction between the isocyanate of Formula 2 andthe polyalkylene glycol monoether of Formula 3 is eflected by mixing thetwo ingredients and heating at an elevated temperature until thereaction is complete. It is generally convenient to employ a mutualsolvent for the two reactants. Suitable solvents include the aromaticsolvents, such as benzene, toluene, and the like. A convenient procedureis to dissolve the polyether in the solvent, making sure that theingredients are dry, and then add the isocyanate to the resultingmixture. The mixture is then heated to a temperature of from C. to 100C. and stirred for several hours. The reaction between the isocyanateand the polyalkylene glycol monoether is an equimolar reaction. However,a slight excess of isocyanate is generally used to assure completereaction of the hydroxyl groups. Generally, the solvent is used in anamount to provide 25 to 50 weight percent solvent. In some cases, it isdesirable to employ a catalyst to increase the rate at which theisocyanate and the polyalkylene glycol monoether react. The use of acatalyst is particularly desirable when the terminal hydroxyl group onthe polyether is a secondary hydroxyl group, such as in polyethersprepared by reacting a simple alcohol, such as butanol, first withethylene oxide and then with 1,2- propylene oxide. Where a catalyst isemployed, it is found that standard tin salt catalysts, such as the tinsalt of 2-ethylhexanoic acid, is satisfactory. The catalyst is generallyemployed in an amount up to about 0.10% by weight tin octoate, based onthe weight of the monoether. After holding the reaction mixture at to C.for One to two hours, the reaction is complete and then, if desired, thesolvent can be removed by vacuum distillation.

This reaction results in the formation of within the scope of Formula 4,which is characterized by a terminal vinyl group. This product may ormay not contain solvent, depending upon the particular reaction stepsconducted. Regardless of whether solvent is present, the urethane ofFormula 4 is reacted with the organohydrogen-polysiloxane of Formula 5in the presence of a catalyst which promotes the addition of the Si-Hgroup of the organohydrogenpolysiloxane across the double bonds of thevinyl-terminated urethane. The preferred reaction between the urethaneand the siloxane involves the reactants in ratios sufiicient to provide5 to percent molar excess of the vinyl-terminated urethane, based on thenumber of siliconbonded hydrogen groups in theorganohydrogenpolysiloxane. The purpose of the excess of unsaturatedgroups is to insure that the reaction removes all of the silicon-bondedhydrogen groups so that none is present in the final product.

Suitable catalysts for the addition of the organohydrogenpolysiloxane tothe vinyl-terminated urethane are the various platinum and platinumcompound catalysts known in the art. These catalysts include elementalplatinum in finely divided state, which can be deposited on charcoal oralumina, as well as various platinum compounds, such as chloroplatinicacid, the platinum hydrocarbon complexes of the type shown in Patents3,159,601Ashby and 3,159,662-Ashby, as well as the platinum alcoholatecomplexes prepared from chloroplatinic acid which are described andclaimed in Patent 3,220,972Lamoreaux.

Regardless of whether elemental platinum or one of the platinum compoundcatalysts or platinum complex catalysts is employed, the catalyst isgenerally used in an amount suflicient to provide about 10- to 10 molesof pa'inum per mole of the vinyl chain-stopped urethane of Formula 4.The reaction is effected by adding the organohydrogenpolysiloxane ofFormua 5 to the urethane, either in the presence or absence of thesolvent used in the preparation of the urethane, and then the reactionmixture is heated to a temperature of 80 to 150 C. after the platinumcompound catalyst is added. After maintaining the reaction mixture atreaction temperature for one to ten hours, the reaction is completedand, where the reaction has taken place in the presence of a solvent,the reaction mixture is heated at a reduced pressure to remove thesolvent. This results in the siloxane-oxyalkylene copolymer of Formula1.

In using the organopolysiloxane-oxyalkylene copolymers of the presentinvention within the scope of Formula la as additives in the preparationof polyurethane foams, the copolymer of Formula 1a is added to the otheringredients of the polyurethane foam re action mixture in theproportions described below. The polyurethane foam reaction mixtures areconventional mixtures we'll known in the art and comprise apolyisocyanate and a polyol.

The polyisocyanates which are useful in the practice of the presentinvention are those well known polyisocyanates which are conventionallyused in the manufacture of polyurethane foams. Generally speaking, thesepolyisocyanates contain at least two isocyanate groups per molecule,with the isocynate groups being separated from each other by at leastthree carbon atoms, i.e., the isocyanate groups are not on adjacentcarbon atoms in the polyisocyanate. These polyisocyanates can bearomatic or aliphatic, and can be characterized by the formula:

where Y represents a polyvalent organic radical having a valence f,where f has a value of at least 2, and preferably from 2 to 3,inclusive. The number of isocyanate groups is, of course, equal to thenumber of free valences a urethane in the radical Y. In general, theradical Y consists preferably of carbon and hydrogen atoms only, but canalso include oxygen atoms. Preferably also, the radical Y is amononuclear aromatic radical. Illustrative of the variouspolyisocyanates which can be employed in the practice of the presentinvention can be mentioned, for example, 2,4-toluene diisocyanate;m-phenylene diisocyanate; methylene-bis-(4-phenylisocyanate);4-methoxy-mphenylene diisocyanate; 1,6-hexamethylene diisocyanate;2,4,6-toluene triisocyanate; 2,4,4-diphenylether triisocyanate;2,6-toluene diisocyanate; 3,3'-bitolyene-4,4-diisocyanate;diphcnylmethane-4,4-diisocyanate;3,3-dimethyldiphenylrnethane-4,4-diisocyanate; triphenylmethanetriisocyanate; diansidine diisocyanate; etc. In addition to using only asingle isocyanate in the production of polyurethane foams, it is alsocontemplated that mixtures of various isocyanates can be employed.

The polyols employed in the practice of the present invention are thosepolyols conventionally used in the manufacture of polyurethane foamproducts. Chemically, these' materials fall into one of two generalcategories. The first is the hydroxyl-containing polyester and thesecond is the hydroxyl-containing polyether. The polyesters areconventionally formed by the reaction of a polyhydric alcohol with adibasic acid. The polyhydric alcohol is employed in excess so that theresulting material contains free hydroxyl groups. Illustrative of thetypes of poly ester-polyol materials employed in the production ofpolyurethane foams are polyesters formed by the reaction between dibasicacids, such as adipic acid, with polyhydric alcohols, such as ethyleneglycol, glycerine, pentaerithritol, sorbitol, and the like. In general,these polyester polyols are prepared so as to contain from about 2 toabout 8 hydroxyl groups per molecule.

The polyether polyols employed in the practice of the present inventionfor the manufacture of polyurethane foams can be subdivided into twogroups, the first of which is a polyalkylene glycol, such aspolyethylene glycol or polypropylene glycol, or mixedpolyethylene-polypropylene glycol. The second type is a polyoxyalkylenedcrivative of a polyhydric alcohol, such as a polyoxyalkylene derivativeof glycerine, trimethylol ethane, trimethylol propane, neopentaglycol,sorbitol, sucrose, etc. These materials are Well known in the art andare prepared by effecting reaction between an alkylene oxide or amixture of alkylene oxides and the polyhydric alcohol. One commOn typeof material is prepared by reacting l,2propylene oxide with glycerine toform a triol containing three polyoxypropylene segments attached to theglycerine nucleus.

These polyester polyols and polyether polyols are characterized bymolecular weights of the order of 350 to 10,000. The type ofpolyurethane foam desiredfiexible, semi-rigid, or rigid-will determinethe functionality and molecular Weight of the polyol used. In general,either the polyester polyol or the polyether polyol can be usedinterchangeably in the manufacture of either rigid polyurethane foams,semi-rigid polyurethane foams or flexible polyurethane foams. Ingeneral, the polyols used in the formation of rigid foams have molecularweights in the range of from about 350 to 1,000. Generally, thesepolyols are triols or higher polyols. For the manufacture of semirigidfoams, the polyol has a molecular weight in the range of about 1,000 to2,500 and is generally a triol or a mixture of a triol with polyols ofhigher functionality. For the manufacture of flexible foams, the polyolhas a molecular weight of the range of from about 2,500 up to 10,000 andis a triol or a mixture of triol and a diol.

Along with the polyisocyanate and the polyol, a blowing agent is foundin the polyurethane foam reaction mixture. The foams are usually blownwith carbon dioxide, halocarbon or a mixture of each. Water included inthe foam formulation reacts with the isocyanate groups and results inthe liberation of carbon dioxide which serves as as blowing agent.However, it is often not desirable to form the low density foams usingthe carbon dioxide generated in situ as the only blowing agent, sincethe generation of carbon dioxide also results in crosslinking of thefoam through disubstituted urea linkages. A high level of such linkagesresults in stilfer foams than would be obtained otherwise.

Accordingly, in those cases where soft foams are desired, the reactionmixture often includes a separate blowing agent, such as a low boiling,inert liquid. The ideal liquid is one which has a boiling point slightlyabove room temperature, i.e. a, temperature of about 20 to 25 C., sothat the heat generated by the exothermic reaction between the hydroxylgroups and the isocyanate will warm the reaction mixture to atemperature above the boiling point of the liquid blowing agent andvaporize it. Suitable blowing agents includes alkanes having appropriateboiling points, but the most desirable blowing agents have been found tobe trichlorofiuoromethane or methylene chloride.

In rigid forms intended for thermal insulation, halocarbons are oftenused exclusively as blowing agents because of the low thermalconductivity of halocarbons as opposed to carbon dioxide or air.Trichlorofiuoromethane is the preferred blowing agent for conventionalsystems, while a mixture of trichlorofluoromethane anddichlorodifluoromethane is used in the well known frothing processes.

Other ingredients often found in the polyurethane foam reaction mixtureare various catalysts. For example, it is often desirable to add acatalyst to facilitate the reaction between Water present in thereaction mixture and isocyanate groups. A typical type of catalyst forthis reaction is a tertiary amine catalyst. These amine catalysts andtheir use are well known in the art and include materials such asN-methylmorpholine, dimethylethanol amine, triethyl amine,N,Ndiethylcyclohexyl amine, dimethylhexadecyl amine, dimethyloctadecylamine, dimethylcocoamine, dimethylsilyl amine, N-cocomorpholine,triethylene diamine, etc.

To catalyze the reaction between the hydroxyl groups of the polyol andthe polyisocyanate, polyurethane foam reaction mixtures often contain acatalyst comprising a metal salt of an organic carboxylic acid. Mostoften, this curing agent is a tin salt, such as tin stearate, dibutyltin dilaurate, tin oleate, tin octoate, etc.

The proportions of the various components of the polyurethane foamreaction mixture may vary within wide limits as is well known in theart. When water is added to the reaction mixture, it is present in anamount sutficient to generate the amount of carbon dioxide desired.Generally, when water is employed, it is present in an amount up toabout parts per 100 parts by weight of the polyol. The polyisocyanate isgenerally present in an excess over the amount theoretically required toreact with both the hydroxyl groups of the polyol and any water presentin the reaction mixture. Generally, the polyisocyanate is present in anexcess equal to about 1 to by weight. When a tertiary amine catalyst ispresent in the reaction mixture, it is generally employed in an amountequal to from about 0.001 to 3.0 parts per 100 parts by weight of thepolyol. When a metal salt curing agent is present, it is generallyemployed in an amount equal to from about 0.1 to 1.0 part per 100 partsby weight of the polyol. When a separate blowing agent is employed, itis generally employed in an amount equal to from about 1 to 50 parts per100 parts by weight of the polyol.

When employing the siloxane-oxyalkylene copolymer of Formula la as anaid in the formation of polyurethane foams, the copolymer is generallypresent in an amount equal to from about 0.25 to 4.0 parts by weight per100 parts by weight of the polyol or mixture of polyols in the reactionmixture. While satisfactory results are obtained using amounts of thecopolymer in excess of about 4.0 parts per 100 parts by weight of thepolyol, e.g., up to about 7.5 parts, no particular advantage is obtainedin employing more than the 4.0 parts by weight.

Polyurethane foams can be prepared by one of two general methodsemploying the siloxane-oxyalkylene copolymer of Formula 1a. In the firstand preferred process, all of the reactants are rapidly mixed togetherand the reaction mixture is allowed to foam. After foaming has beencompleted, the resulting-foam can be cured if desired by heating atelevated temperatures, e.g., a temperature of from about to C. forseveral hours. Alternatively, the foam can be stored at room temperatureuntil complete cure has been effected in times of from 24 hours to 48hours or more.

In the second process, a prepolymer is formed from the polyol and thepolyisocyanate to give a prepolymer containing excess polyisocyanate.This prepolymer is then mixed with the other reactants, such as water,tertiary amine catalyst, blowing agent, curing catalyst, andsiloxaneoxyalkylene copolymer of Formula 1a and allowed to foam. In amodification of the second process, the polyisocyanate and a portion ofthe polyol are reacted together to form a base resin. When foaming isdesired, the remainder of the polyol, as well as the other ingredientsof the reaction mixture, are added to the base resin and the mixture isstirred andallowed to foam. Again, curing can be effected at roomtemperature or at an elevated temperature.

Regardless of the foaming process in which the polysiloxane-oxyalkylenecopolymer of Formula 1 is employed, and regardless of whether thecomponents of the reaction mixture are such as to produce rigid foams,semirigid foams or flexible foams, the use of these copolymers resultsin foams having small, uniform cells and desirably low densities.

Because of the complexity of the well known technology surrounding themanufacture of polyurethane foam of all types, no attempt will be madehere to discuss the many variations in technique and formulations whichcan 'be employed. For further details on the technology of polyurethanefoams, reference is made to the voluminous patent and technicalliterature on the subject, especially Chemistry and Technology, volumesI and II, I. Saunders and K. Frisch, Interscience, New York (1964).

The use of the siloxane-alkylene copolymers of the present invention inheat-sensitive latices is described in detail and claimed in theapplication of Norman G. Holdstock, Ser. No. 644,055, filed concurrentlyherewith and assigned to the same assignee as the present invention.Heat-sensitive latices have the property of coagulating to form a closedfilm when heated to a certain temperature. These latices, which can belatices of natural rubber or of many types of synthetic rubbers orresins require some type of sensitizing agent. One of the common typesof sensitizers has been metal nitrates and, in particular, calciumnitrate. Recently, various types of silicone materials have been used toheat-sensitize latices, but their use has required higher sensitizationtemperatures or higher concentrations of sensitizer or both. Desirably,this sensitization is effected with a minimum of additive to reduce thecost of sensitization baths.

The siloxane-oxyalkylene copolymers of the present invention are usefulin sensitizing natural and synthetic latex formulations employing verysmall amounts of the copolymer and with relatively low coagulation orsensitization temperatures. These latex baths are generally well knownin the art and comprise a major portion of the latex, a minor amount ofvarious curing and vulcanizing agents and vulcanizing accelerators, aswell as the sensitizing agent which is the copolymer of Formula lb.After thoroughly mixing the ingredients, a mold heated to a temperatureabove the sensitization or coagulation temperature is dipped into thesensitized bath and, as soon as the heated mold heats the portion of thebath in contact with the mold to the coagulation temperature, the latexin the bath adjacent the mold surface coagulates to form a uniform filmaround the mold. The mold is withdrawn from the bath and heated toremove solvent and to cure the formed article. The aforementionedcopending Holdstock application is hereby incorporated by reference intothe present application for details on the use of the compositionswithin the scope of Formula 11) in the sensitization of rubber latices.

The following examples are illustrative of the practice of my inventionand are not intended for purposes of limitation.

EXAMPLE 1 To a reaction vessel was added a solution of 750 g. ofpolyethylene glycol monomethylether containing approximately 16oxyethylene groups and 300 g. of toluene. This resulting solution wasrefluxed to insure the removal of water and cooled to room temperature.A 10% molar excess (91 g.) of allylisocyanate was added and the reactionmixture was heated at 100 C. for 3 hours. Then the toluene and excessallylisocyanate were removed by distillation at 150 C. and 10 mm. Thisresulted in a urethane within the scope of Formula 4, where R is methyl,A is methylene, n is 2, and x is approximately 16. A siloxaneoxyalkylenecopolymer within the scope of the present invention was prepared bycharging to a reaction vessel 83.3 g. of the urethane prepared above,26.3 g. of a trimethylsilyl chain-stopped polysiloxane which, on theaverage, contained 2 trimethylsiloxane chain-stopping units, 6dimethylsiloxane units and 3 methylhydrogensiloxane units per molecule,83 g. of toluene and a sufficient amount of the platinum-ethylenecomplex described in the aforementioned Patent 3,159,601Ashby, toprovide 10- gram atoms platinum per mole of the urethane. The reactionmixture was heated at reflux for about 10 hours and then the pressurewas lowered and the temperature raised sufficiently to strip off thetoluene solvent. This resulted in a copolymer which was a soft waxwithin the scope of Formula 1, where R and R are methyl, A is methylene,is is 2, x is 16, a is 0.27 and b is 1.91.

EXAMPLE 2 In this example, a siloxane-oxyalkylene copolymer was preparedby mixing 83.3 g. of the urethane prepared in Example 1, 24.4 g. of atrimethylsilyl chain-stopped polysiloxane containing an average of 2trimethylsiloxane units, 12 dimethylsiloxane units and 6methylhydrogensiloxane units per molecule, 85 g. of xylene and asufficient amount of chloroplatinic acid to provide 10" gram atoms ofplatinum per mole of the urethane. This reaction mixture was refluxedfor two hours to produce a siloxane'oxyalkylene copolymer within thescope of Formula 1 in which R and R are methyl, A is methylene, n is 2,x is 16, where a is 0.30 and b is 1.80. This material was a soft wax atroom temperature.

EXAMPLE 3 Following the procedure of Example 1, a urethane within thescope of Formula 4 was prepared from a reaction mixture of 91 g.allylisocyanate, 300 g. toluene and 350 g. of the monomethylether of apolyethylene glycol having an average of 7 oxyethylene groups permolecule. Following the procedure of Example 1, the urethane was addedto an organopolysiloxane whose average molecule contained 2trimethylsiloxane units, 35 dimethylsiloxane units and 17methylhydrogenpolysiloxane units, employing 190 g. of the urethane, 110g. of the siloxane, 250 g. of toluene, and sufficient chloroplatinicacid to provide gram atoms of platinum per mole of the urethane. Thereaction was effected by refluxing the mixture for 5 hours and thenlowering the pressure and increasing the temperature to strip off thetoluene solvent. This resulted in a composition within the scope ofFormula 1 in which R and R are methyl, A is methylene, n is 2, x is 7, ais 0.31 and b is 1.75.

This material is a clear liquid having a viscosity of 350 centistokes at25 C.

EXAMPLE 4 Following the procedure of Example 1, a urethane was preparedfrom 1,000 g. of the monomethylether of a polyethylene glycol containing21 oxyalkylene groups, 91 g. of allylisocyanate and 500 g. of toluene.The resulting urethane was reacted with a methylhydrogenpolysiloxane inwhich the average molecule contained 2 trimethylsiloxane units, 6dimethylsiloxane units, and 1 methylhydrogenpolysiloxane unit. Inparticular, 120 g. of the urethane, 26 g. of the siloxane, and g. ofxylene were reacted in the presence of a suificient amount of theplatinum alcoholate catalyst of Example 1 of Patent 3,220,972Lamoreaux,to provide 10- gram atoms of platinum per mole of the urethane. Afterrefluxing for 1 /2. hours, the reaction was completed to produce asiloxane-oxyalkylene copolymer within the scope of Formula 1 in which Rand R are methyl, A is methylene, n is 2, x is 21, a has a value of0.27, and b has a value of 1.91. This product was also a wax, but not assoft as the wax of Example 1.

EXAMPLE 5 Following the procedure of Example 1, a urethane was preparedfrom a reaction mixture comprising 1700 g. of a monobutyl ether of anethylene glycol-propylene glycol copolymer, 91 g. of allylisocyanate,500 g. of toluene and 0.85 g. of tin octoate. The monobutyl ether hadbeen prepared by first condensing butanol with a mixture of ethyleneoxide and 1,2-propylene oxide to produce a monoether containing anaverage of 17 ethylene oxide and 13 oxypropylene-1,2 groups permolecule. Then 157 g. of the urethane prepared above were reacted with40 g. of a methylhydrogenpolysiloxane in the presence of 200 g. tolueneand sutlicient chloroplatinic acid to provide 10 gram atoms of platinumper mole of the urethane. The polysiloxane was a trimethylsilylchainstopped methylhydrogenpolysiloxane containing an average of 2trimethylsiloxane units, 15 dimethylsiloxane units and 3methylhydrogensiloxane units per molecule. The reaction mixture wasrefluxed at a temperature of C. for 3 /2 hours to produce the productand the pressure was then reduced to 10 mm. and the temperatureincreased to a pot temperature of about C. to remove the toluenesolvent. This product was a liquid having a viscosity of 1650centistokes at 25 C. The material was a siloxane-oxyalkylene blockcopolymer within the scope of Formula 1 in which R is methyl, R isbutyl, A is methylene, n has a value of 2.43, x has a value of 30, a hasa value of 0.15 and b has a value of 1.95.

EXAMPLE 6 In all of the preceding examples, the urethane employed hadbeen added to an organopolysiloxane in which all of the SiH groups werepresent as a portion of a methylhydrogensiloxane unit in the chain. Inthe present example, the siloxane contains silicon-bonded hydrogengroups both along the chain in methylhydrogensiloxane units and in thetwo chain ends which are dimethylhydrogensiloxane units. In particular,157 g. of the urethane prepared in Example 5 was reacted with 40 g. ofthe siloxane and 200 g. of toluene in the presence of 10 gram atoms ofplatinum (as chloroplatinic acid) per mole of the urethane. The siloxanecontained an average of 2 dirnethylhydrogensiloxane units per molecule,17 dimethylsiloxane units per molecule, and l methylhydrogensiloxaneunit per molecule. The reaction was effected by heating the mixture at115 C. for 15 hours at atmospheric pressure and then lowering thepressure to 10 mm. while raising the temperature to 150 C. to removetoluene. This resulted in a clear liquid siloxaneoxyalkylene copolymerhaving a viscosity of 1950 centistokes at 25 C. This copolymer waswithin the scope 11 of Formula 1 when R is methyl, R is butyl, A ismethylene, n has an average value of 2.43, x is 30, a is 0.15, and b is1.95.

EXAMPLE 7 This example illustrates the preparation of a copolymer of thepresent invention from an organopolysiloxane having the same molecularWeight and the same percentage of Si-H groups as in Examples and 6, butin which the siloxane contains a monomethylsiloxane unit and in whichall three SiH groups are present as part of a dimethylhydrogensiloxaneunit. The specific reactants were 1.57 g. of the urethane of Example 5,40 g. of the siloxane, 200 g. of toluene and an amount of chloroplatinicacid sufficient to form 10 gram atoms platinum per mole of urethane. Thesiloxane had average molecules with one monomethylsiloxane unit, 16dirnethylsiloxane units, and 3 dimethylhydrogensiloxane units. Themixture was refluxed for 3 hours to produce the copolymer and heatedfurther at reduced pressure to strip off the L toluene solvent. Thisresulted in a clear fluid having a viscosity of 1600 centistokes at 25C. and being within the scope of Formula 1 when R is methyl, R is butyl,A is methylene, n has an average value of 2.43, x is 30, a has a valueof 0.15 and b is 1.95.

EXAMPLE 8 In this example, a urethane Was prepared by reacting aphenoxy-stopped copolymer of ethylene glycol and propylene glycol withallylisocyanate. The monophenyl ether was prepared by condensing phenolwith 1,2-propylene oxide and then with ethylene oxide to produce amonophenyl ether containing 25 oxyethylene groups and 25 oxypropylene-LZgroups. A urethane was prepared by reacting 2800 parts of thismonophenyl ether with 91 parts of allylisocyanate in 1200 parts oftoluene. This urethane was within the scope of Formula 4 when A ismethylene, R is phenyl, n has an average value of 2.5, and x has a valueof 50. A copolymer was prepared by mixing 138 g. of this urethane with30 g. of a methylhydrogenpolysiloxane, 168 g. of toluene, and asufficient amount of the aforementioned platinum alcoholate catalyst toprovide 10- gram atoms of platinum per mole of the urethane. Themethylhydrogenpolysiloxane contained an average of 1 monomethylsiloxaneunit, 20 dimethylsiloxane units, and 3 dimethylhydrogensiloxane unitsper molecule. This reaction was effected by heating for about 4 hours ata temperature of 110 C. and then reducing the pressure and raising thetemperature to remove the toluene solvent. This resulted in a liquidsiloxane-oxyalkylene copolymer having a viscosity of 4,500 centistokesat C. and falling within the scope of Formula 1 when R is methyl, R isphenyl, A is methylene, n has an average value of 2.5, x has a value of50, a has a value of 0.12 and b has a value of 1.95.

EXAMPLE 9 Following the procedure of earlier examples, 187 g. of thesame urethane prepared in Example 5 from allyl isocyanate and themonobutoxy ether of the ethylene glycol-propylene glycol copolymer wasadded to a mixture of 125 g. of a trimethylsilyl chain-stoppedmethylhydrogenpolysiloxane containing an average of 3methylhydrogensiloxane units per molecule and sufiicient chloroplatinicacid to provide 10* gram atoms of platinum per mole of the urethane.This reaction mixture was heated at a temperature of about 90 C. for aperiod of 4 to 5 hours to complete reaction :between the silicon-bondedhydrogen atoms and-the allyl radicals of the allyl urethane. Theresulting product was a liquid having a viscosity of about 1500centistokes at 25 C. This material was a siloxaneoxyalkylene blockcopolymer within the scope of Formula 1 in which R is methyl, R isbutyl, A is methylene, n has an average value of 2.43, x has a value of30, a has a value of 0.6, and b has a value of 1.8.

12 EXAMPLE 10 A urethane was prepared fromallyl isocyanate and anonylphenol-stopped ethylene oxide-propylene oxide polyether. Inparticular, the polyether was prepared by condensing nonylphenol with1,2-propylene oxide and then with ethylene oxide to produce anonylphenol ether containing an average of 17 ethylene oxide and 13oxypropylene-1,2 groups per molecule. The urethane was prepared byadding 200 g. toluene to 317 g. of the nonylphenol chain-stoppedcopolymer of ethylene glycol and propylene glycol and azeotroping offwater from the reaction mixture. The reaction mixture was then cooled toC. and 0.15 g. tin octoate was added. The reaction mixture was heateduntil the coupling reaction had been completed as evidenced by infraredanalysis. Then toluene and unreacted allyl isocyanate were stripped fromthe reaction mixture. To 12.9 g. of the trimethylsilyl chain-stoppedmethylhydrogenpolysiloxane of Example 9 was added 177 g. of the urethaneand sufficient chloroplatinic acidhexahydrate to provide 10- gram atomsof platinum per mole of the urethane. This reaction mixture was heatedat a temperature of C. for 10 hours until all of the silicon-bondedhydrogen atoms had reacted with the allyl radicals of the urethane toproduce a clear liquid having a viscosity of 2200 centistokes at 25 C.This material was a siloxaneoxyalkylene block copolymer within the scopeof Formula 1 in which R is methyl, R' is nonylphenyl, A is methylene, nhas an average value of 2.43, x is 30, a has a value of 0.6, and b has avalue of 1.8.

EXAMPLE 11 The procedure of Example 9 was followed in adding 187 g. ofthe allyl urethane of Example 5 to 8.3 g. of a trimethylsilylchain-stopped methylhydrogenpolysiloxane containing an average of 7methylhydrogensiloxane units per molecule in the presence of sufficientchloroplatinic acid to provide 10- gram atoms of platinum per mole ofurethane. This product was a clear oil having a viscosity of 1800centistokes at 25 C. This siloxaneoxyalkylene copolymer was within thescope of Formula 1 when R is methyl, R is butyl, A is methylene, n hasan average value of 2.43, x is 30, a has a value of 0.78, and b has avalue of 1.44.

EXAMPLE 12 Following the general procedure of Example 9, g. of the allylurethane prepared in Example 5 was added to a mixture of 7.6 g. of atrimethylsilyl chain-stopped methylhydrogenpolysiloxane having anaverage of 10 methylhydrogensiloxane units per molecule in the presenceof sufiicient chloroplatinic acid hexahydrate to provide 10 gram atomsof platinum per mole of urethane. After heating this reaction mixturefor 8 hours at 120 C., the silicon-hydrogen groups of the siloxane hadreacted with the allyl radicals to produce a clear siloxane-oxyalkylenecopolymer having a viscosity of about 2500 centistokes at 25 C. Thiscopolymer was within the scope of Formula 1 when R is methyl, R isbutyl, A is methylene, n has an average value of 2.43, x is 30, a has avalue of 0.83, and b has a value of 1.33.

EXAMPLE 13 Following the general procedure of Example 9, g. of the allylurethane prepared from allyl isocyanate and the butoxy chain-stoppedcopolymer of ethylene oxide and propylene oxide of Example 5 Was addedto 6.0 g. of a trimethylsilyl chain-stopped methylhydrogenpolysiloxanecontaining an average of about 25 methylhydrogensiloxane groups permolecule. The reaction was effected by heating the reactants in thepresence of sufiicient chloroplatinic acid hexahydrate to provide 10'gram atoms platinum per mole of the urethane and the reaction mixturewas heated at 110 C. for 10 hours. The resulting siloxaneoxyalkylenecopolymer had a viscosity 13 of 2500 centistokes at 25 C. and was withinthe scope of Formula 1 when R is methyl, R is butyl, A is methylene, nhas an average value of 2.43, x is 30, a has a value of 0.93, and b hasa value of 1.15.

The foregoing examples have illustrated the preparation of a number ofsiloxane-oxyalkylene copolymers within the scope of the presentinvention. The following Examples 14 through 22 illustrate the processof the present invention which involves the use of thesiloxaneoxyalkylene copolymers of Formula 1a in the formation of variouspolyurethane foam formulations.

EXAMPLE 14 A conventional rigid polyurethane foam was prepared byrapidly mixing together 100 g. of crude toluene diisocyanate with apremix consisting of 109 g. of a sucrosebased polyol (hydroxyl No. 490),40 g. of trichlorofluoromethane, 0.3 g. of triethylene diamine, andallowing the mixture to stand. Immediately upon completion of themixing, the reaction mixture began to form bubbles and began to rise.However, the bubbles burst almost as fast as they formed and no urethanefoam product was obtained. When this same procedure was followed exceptthat the reaction mixtures contained 1.0 g. of any of thesiloxane-oxyalkylene block copolymers of Examples 1 through 4, per 100parts of the polyol, the resulting product foamed to a uniform, fine,closed cell polyurethane having a density of less than 1.7 pounds percubic foot.

EXAMPLE 15 Five flexible polyurethane foam formulations were prepared,each of which contained 100 g. of a triol, which was the 3,000 molecularweight condensation product of glycerine with propylene oxide, 49 g. of80/20 toluene diisocyanate, 4.0 g. water, 0.10 g. triethylene diamine,

0.25 g. stannous octoate. The first four mixtures included 1.0 g. of oneof the siloxane-oxyalkylene copolymers of Examples through 8respectively. In each of the four cases, as soon as the reactants weremixed, the composition began to foam until a uniform, open, fine-celledEXAMPLE 16 A flexible polyurethane foam was prepared by rapidly mixing45 g. of the triol of Example 10, 35 g. of a polyol derived from1,1,1-trimethylolpropane and capped with ethylene oxide, 20 g. of apolypropylene glycol having a molecular weight of about 2,000, 0.3 g.stannous octoate, 42.9 g. 80/20 toluene diisocyanate, 0.1 g. triethylenediamine, 3.4 g. water and 0.25 g. of the siloxane-oxyalkylene blockcopolymer prepared in Example 5. The trimethylolpropane derivative had amolecular weight of about 4,500 and was prepared by reactingpropylene-1,2-oxide with trimethylolpropane. This mixture of ingredientsbegan to foam immediately and produced a polyurethane foam having small,uniform, open cells and with a density of about 1.9 pounds per cubicfoot.

EXAMPLE 17 A polyurethane foam was prepared by rapidly mixing 100 g. ofthe triol of Example 11, 0.2 g. stannous octoate, 47 g. 80/20 toluenediisocyanate, g. trichlorofiuoromethane, 0.1 g. triethylene diamine, 3.7g. water and 4.0 g. of the orgauosiloxane-oxyalkylene block copolymer ofExample 6. This resulted in a foam having uniform, small, open cellswith a density of about 1.2 pounds per cubic foot.

EXAMPLE 18 A polyurethane foam was formed by rapidly mixing 100 g. ofthe triol of Example 10, 0.5 g. stannous octoate,

43 g. toluene diisocyanate, 15 g. trichlorofluoromethane, 0.15 g.triethylene diamine, 3.4 g. water and 2.0 g. of theorganopolysiloxane-oxyalkylene block copolymer of Example 8. Thismaterial foamed to a flexible foam having small, uniform open cells andand a density of about 1.2 pounds per cubic foot.

EXAMPLE 19 A rigid polyurethane foam was prepared by mixing 75.6 g. of aprepolymer prepared by reacting a hexol derived from sorbitol andpropylene oxide with toluene diisocyanate in the ratio of 4.5equivalents of toluene diisocyanate per equivalent of the hexol, 55.6 g.of the aforementioned hexol, 27.8 g. of a mixture oftrichlorofluoromethane and triethylene diamine in the ratio of 30 partsof the halogenated methane to 0.8 part of the diamine, and 0.25 g. ofthe siloxane-oxyalkylene block copolymer of Example 1. The hexol had amolecular weight of about 700 and contained 6 hydroxyl chainstoppedpolyoxypropylene groups attached to the sorbitol nucleus. This mixturefoamed to a white, rigid polyurethane foam having small, uniform cellsand a density of 2.0 pounds per cubic foot.

EXAMPLE 20 A rigid polyurethane foam was prepared by mixing 160 g. of atriol derived from fiuoroglucinol and propylene oxide, 15 g. ofN,N,N,N-tetra-kis-(Z-hydroxypropyl)- ethylene diamine, 1.2 g. of dibutyltin dilaurate, 137 g. of crude toluene diisocyanate, 57 g. oftrichlorofluoromethane, and 3.2 g. of the siloxane-oxyalkylene blockcopolymer of Example 2. This material foamed to a rigid polyurethanehaving small, uniform cells and a density of 1.3 pounds per cubic foot.

EXAMPLE 21 A rigid polyurethane foam was prepared by mixing g. of asorbitol polyol prepared by reacting 1,2-propylene oxide with sorbitolto produce a hexol having a molecular weight of about 700, 96 g. ofcrude toluene diisocyanate, 0.3 g. triethylene diamine, 35 g.trichlorofiuoromethane, and 1.0 g. of the siloxane-oxyalkylene copolymerof Example 2. This resulted in a rigid polyurethane foam having small,closed cells, and a density of 2.0 pounds per cubic foot.

EXAMPLE 22 A rigid polyurethane foam was prepared by mixing 100 g. of acommercial polyether based on methyl glucoside, parts of apolyisocyanate available under the tradename PAPI, 36 g. oftrichlorofluoromethane, 0.3 g. triethylene diamine, and 1.0 g. of thesiloxane-oxyalkylene copolymer of Example 3. The polyether employed inthis example had been prepared by condensing 1,2-oxypropylene withalpha-methylglucoside to produce a material having a molecular weight of520. The polyisocyanate was a triisocyanate containing 3 phenyl nucleiseparated from each other by methylene groups with each phenyl nucleuscontaining an isocyanate group. Upon mixing this material and allowingit to stand, it formed a rigid, fine, closed cell polyurethane foamhaving a density of about 1.9 pounds per cubic foot.

The following Examples 23 and 24 illustrate the use of compositionswithin the scope of Formula 1b as sensitizers for heat-sensitivelatices. For many other illustrations of the use of materials within thescope of Formula 111 as sensitizers, reference is again made to theaforementioned copending application of Norman G. Holdstock, filedconcurrently herewith, which describes the use of many of suchcompositions within the scope of Formula lb in many different latexformulations. Such use is the invention of Norman G. Holdstock and isclaimed in the aforementioned copending application. This copendingapplication is incorporated by reference into the present applicationfor further illustrations of the utility of the materials of Formula 1b.

15 EXAMPLE 23 A series of multi-part compositions were made up. Part Aof each composition consisted of 210 parts of anacrylonitrile-methacrylic acid copolymer latex having a solids contentof 47 percent by weight. Part B of each composition consisted of 0.5part of one of the siloxaneoxyalkylene copolymers of Examples 9 through12, 2.0 parts of a commercial emulsifying agent which was a nonylphenolether of a polyethylene glycol, and 4.0 parts water. Part C of eachcomposition consisted of 2.5 parts of colloidal sulfur, 2.5 parts finelydivided zinc oxide, 0.8 part of zinc diethyl dithiocarbamate, 0.61 partof a condensation product of sodium naphthylene sulfonate withformaldehyde, and 11.4 parts water. For each composition, Part B wasadded to Part A with good agitation and Part C was then added and themixture was stirred until well mixed. The coagulation temperature ofeach of the mixtures was determined by measuring the minimum temperatureat which a heated probe would cause coagulation of the mixture to form arubber layer on the outside of the probe. For the composition using thecopolymer of Example 9, the coagulation temperature was 42 C., for theExample 10 material the temperature was 40 C., for the Example 11 andExample 12 material the temperature was 36 C.

EXAMPLE 24 To 200 parts of a 50 percent solids latex of anacrylonitrile-butadiene-methacrylic acid copolymer was added 0.5 part ofthe copolymer of Example 13. The minimum coagulation temperature forthis mixture was 58 C.

While the foregoing examples have illustrated many of the embodiments ofmy invention, it should be understood that my invention, in its broaderaspects, involves the siloxane-oxyalkylene copolymers of Formula 1.Generally, these block copolymers are designed so that the copolymercomprises approximately 3 to 70% by weight organopolysiloxane portionand 30 to 97% by weight of the oxyalkylene portion which includes theurethane linkage. Again, while the oxyethylene group of the oxyalkyleneportion of the copolymer can be any single oxyalkylone group within thescope described above, the oxyalkylene portion can also comprise amixture of two or more different oxyalkylene groups. Variouscompositions within the scope of the present invention have a specialutility for particular uses. Thus, for use as foam cell size controlagents in the manufacture of rigid polyurethane foams, it is preferredthat the copolymer comprise about 15 to 50% by weight siloxane with thevalue of subscript a of Formula 1 being from about 0.20 to 0.50 urethanegroups per silicon atom. In such case, the polyether can be preferablyall ethylene oxide or a mixture of both ethylene oxide and higheroxyalkylene groups. In contrast to this, for the manufacture of flexiblepolyurethane foams, it is preferred to use copolymers within the scopeof Formula 1 in which the composition comprises from about 15m 30% byweight of silicone and with the value of subscript a in Formula 1 beingnear the lower portion of the range of values set for a, i.e., fromabout 0.05 to 0.20. Preferably, for copolymers used in the manufactureof flexible urethane foams, the oxyalkylene comprises a mixture of bothethylene oxide and propylene oxide. For other surfactant applications,the value of the various components and radicals and subscripts inFormula 1 can var within the full range described for these items.

For the manufacture of siloxane-oxyalkylene copolymers of Formula 1which are to be used as latex coagulants, the block copolymers aredesigned so that the oxyalkylene portion of the copolymer comprisessignificantly more than organopolysiloxane portion. For example, theoxyalkylene portion advantageously comprises from 80 to 97 percent byweight of the total copolymer. Also, the oxyalkylene portion is presentin a relatively high ratio, i.e., the value of subscript a of Formula 1is in the range of 16 from 0.5 to 1.00, preferably in the range of fromabout 0.75 to 1.00.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An organosiloxane-oxyalkylene copolymer having the formula:

wherein R is a member selected from the group consisting of monovalentaliphatic hydrocarbon radicals of not more than 8 carbon atoms,halogenated monovalent aliphatic hydrocarbon radicals of not more than 8carbon atoms and 3 halogen atoms, mononuclear and binuclear aryl of notmore than 10 carbon atoms, halogenated mononuclear and binuclear aryl ofnot more than 10 carbon atoms and 3 halogen atoms and cyanoalkyl of notmore than 4 carbon atoms, R is a member selected from the groupconsisting of alkyl of not more than 7 carbon atoms and mononuclear andbinuclear aryl of not more than 10 carbon atoms, A is a divalenthydrocarbon radical containing no more than about 7 carbon atoms, a hasa value of from 0.05 to 1.00,- inclusive, 1: has a value of from 1.12 to2.25, inclusive, the sum of a plus b is equal to from 2.02 to 2.40,inclusive, :1 has a value of from 2 to 4, inclusive, and x has a valueof at least 5.

2. The copolymer of claim 1 in which A is methylene.

3. The copolymer of claim 1 in which R is methyl and A is methylene.

4. The copolymer of claim 1 in which R is methyl, A is methylene, and Ris an alkyl radical.

5. Copolymer of claim 1 wherein R is alkyl and A is alkylene.

6. Copolymer of claim 1 wherein R is methyl, A is alkylene and R ist-butyl.

7. An organosiloxaneoxyalkylene copolymer of the formula:

wherein R is a member selected from the group consisting of monovalentaliphatic hydrocarbon radicals of not more than 8 carbon atoms,halogenated monovalent aliphatic hydrocarbon radicals of not more than 8carbon atoms and 3 halogen atoms, mononuclear and binuclear aryl of notmore than 10 carbon atoms, halogenated mononuclear and binuclear aryl ofnot more than 10 carbon atoms and 3 halogen atoms and cyanoalkyl of notmore than 4 carbon atoms, R is a member selected from the groupconsisting of alkyl of not more than 7 carbon atoms and mononuclear andbinuclear aryl of not more than 10 carbon atoms, A is a divalent hydrocarbon radical containing no more than about 7 carbon atoms, j has avalue of from 0.50 to 1.00, inclusive, k has a value of from 1.12 to1.90, inclusive, the sum of 1 plus k is equal to from 2.02 to 2.40,inclusive, n has a value of from 2 to 4, inclusive, and x has a value ofat least 5.

8. Copolymer of claim 7 wherein R is alkyl and A is alkylene.

9. Copolymer of claim 7 wherein R is alkyl, A is alkylene and R is loweralkyl.

10. Copolymer of claim 7 wherein A is methylene.

11. Copolymer of claim 7 wherein R is methyl and A is methylene.

12. Copolymer of claim 7 wherein R is methyl, A is methylene, and R islower alkyl.

No references cited.

TOBIAS E. LEVOW, Primary Examiner P. F. SHAVER, Assistant Examiner US.Cl. X.R. 2602.5, 46.5

